Amorphous Fe78Si9B13 alloy: An efficient and reusable photo-enhanced Fenton-like catalyst in degradation of cibacron brilliant red 3B-A dye under UV–vis light

Abstract

The development of new functional applications of amorphous alloy is an active and challenging topic. In this work, amorphous Fe78Si9B13 alloy, a photo-enhanced Fenton-like catalyst, exhibits excellent functional ability in degrading an azo dye. This study reports the dramatic performance gains achieved for photo-enhanced Fenton-like degradation of cibacron brilliant red 3B-A (BR3B-A) dye aqueous solutions, the reusability of amorphous Fe78Si9B13 alloy ribbon catalysts, and the reaction kinetics (k) of the process. The individual and synthetical effects of the various reaction parameters are investigated by employing an orthogonal matrix (L16(45)) experimental methodology. The investigation evaluates the impact of these parameters on the degradation process, in order to demonstrate that UV–vis light could continuously induce hydroxyl radicals (OH) to be generated in the dye aqueous solution and significantly enhance the rate of dye degradation and mineralization. The experimental results show that nearly 100% color removal is achieved within 5min under conditions of 2.0g/L Fe78Si9B13 ribbons, 0.5M H2O2 and pH 2. UV–vis light intensity ranging from 0 to 7.7μW/cm2 enhances a dramatic improvement in color removal from 78% at 200min to 98% at 60min and an improvement in the reaction kinetics (k) from 0.0413at 0μW/cm2 of light irradiation to 0.2901 at 7.7μW/cm2 of light irradiation under conditions of 2.0g/L Fe78Si9B13 ribbons, 0.5M H2O2 and natural pH 6.45. The production of OH is investigated by adding tertiary butanol, resulting in a sharp decrease of dye color removal. Structural characterizations of as-received amorphous Fe78Si9B13 ribbons and of recycled Fe78Si9B13 ribbons are also investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectrophotometers (UV–vis DRS), scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS); the results reveal a slight decay of the reused Fe78Si9B13 ribbons, along with a gradual precipitation of crystallized α-Fe, iron oxide and SiO2 on the ribbon surface over the few cycles of usage.